應用於眼壓監測之無線射頻標籤的設計、製作與量測

Abstract

為了針對眼壓進行長時間的監測，本論文提出一個以無線方式讀取隱形眼鏡中眼壓感測器的系統，此系統使用了無線射頻辨識技術（Radio Frequency Identification，縮寫RFID）作為通訊的基礎，進行了RFID感測標籤晶片內數位基頻電路、收能天線與傳能天線的設計與製作，實現了一個前測試用的無線眼壓感測標籤。 考慮隱形眼鏡尺寸等天線設計條件限制，本論文使用860 ~ 960 MHz的通訊頻段，並以單環天線為主體進行天線設計，在天線尺寸遠小於波長的近場情況下，利用磁感耦合提高傳能的效率。 實驗結果證實，此感測標籤可在2 cm通訊距離與12.6 dBm射頻功率下完成無線感測器讀取，並在30 dBm射頻功率下達到最大7 cm的感測距離，此結果符合本論文提出的應用需求。同時進行了下一代收能天線的設計與模擬，根據前測試結果，計算出以18.2 dBm射頻功率可完成2 cm通訊距離下的無線感測器讀取。

In order to achieve long-term intraocular pressure (IOP) monitoring, this thesis presents a wireless readout system based on radio frequency identification (RFID) technology used to readout contact lens IOP sensor device. A digital baseband circuit, receive antenna and transmit antenna has been designed and fabricated to implement a pre-testing wireless IOP sensing tag. Considering the restriction on antenna size which is limited by contact lens, this thesis used 860 ~ 960 MHz as communication frequency band, designed a single-loop like antenna using inductive coupling to obtain higher energy transmission efficiency in near field under the conditions that the size of antenna is much smaller than the wavelength. The proposed sensing tag can perform 2 cm wireless sensing with 12.6 dBm RF power, and reached the maximum sensing distance of 7 cm under 30 dBm, which has met the requirement of our application. Furthermore, a next generation receive antenna has been designed and simulated, according to the pre-testing result, a 18.2 dBm RF power is needed to accomplish wireless sensing at distance of 2 cm.